Just to say this is a big introduction (from starts to experts) to the network stuff through the magnific language that is perl.Do you want to be a hacker? do you know enought of perl? Do you feel the only you need to be a hacker is some specific book that prepares to it? this is the one, BUY IT, at the end you will think this is one of the best books you have already read, i promise you.(if you already know the net, it explains how to do the stuff in perl in an exciting way!)

I would aggree with all the positive reviews for this book on most aspects. With re to just ordinary, intro SQL..this book is great ! My feeling is that even the most technically-challenged people will feel comfortable going thru this book and become productive. But IMHO, SQL is definitely NOT PL/SQL. I can't help but think that the title is not right. I mean there are only 2 chapters pertaining to PL/SQL out of 9. So if you want to learn SQL in 7 days: Get and keep this book !(You may need to re-read it) But if you're looking to get to the the next level, this book may not be what you really NEED. It'll definitely whet your "appetite" though. To be honest, i found it hard to plunk $40 for 2 chapters worth of material that i'm interested in. So i read them in the bookstore. But i'll definitely save my lunch money for the next real PL/SQL book by Mr Allen !

For those seeking to expand their basic knowledge of networks, I was impressed with the graphics, illustrations, and technical descriptions. For what "holes" you may have in understanding network basics, this is a good one to gain an overview. Other Que books published have also been winners: "How PC's Work" and "How the Internet Works".